The present invention relates to a mixing apparatus for mixing a reagent for use in an automatic chemistry analyzer and, more particularly to a mixing apparatus for mixing a reagent for use in an automatic chemistry analyzer in which a sample and a reagent are reacted in a reaction cuvette and an analysis operation in the automatic chemistry analyzer is carried out.
The present invention relates to a mixing apparatus for mixing a reagent for use in an automatic chemistry analyzer in which a plurality of kinds of reagents corresponding to a plurality of measurement items are prepared on a reagent table and are successively supplied into reaction cuvettes on a reaction table so as to cause reactions between samples and the respective reagents thereby automatically analyzing the samples.
The automatic chemistry analyzer includes a reaction table, a sample table and a reagent table all arranged separately from each other. The automatic chemistry analyzer has a sample table having sample vessels and a reaction table coaxial with the sample table. The automatic chemistry analyzer also has a plurality of reagent vessels corresponding to different measurement items. In an analysis operation, the samples and the reagents are supplied into the reaction vessels by a pipetting apparatus.
The automatic chemistry analyzer according to the present invention is a biochemistry automatic chemistry analyzer or an immunology automatic chemistry analyzer etc..
In a conventional discrete type automatic chemistry analyzer, a reagent solution being received in a reagent vessel is pipetted into a reaction cuvette and a sample and a reagent are reacted in the reaction cuvette. The reagent solution that is pipetted into the reaction cuvette is required to be a homogeneous type solution.
However, recently there has been developed in the automatic chemistry analyzer field a method of dissolving tablets as a reagent immediately before the use thereof or a method of using a suspension solution in which an insoluble powder is suspended. In particular, a reagent consisting of small size particles having an antibody coated analyzer a reagent being coated an antibody at a small thereon has been utilized.
In this case, when the reagent is left in the mixing apparatus concentration of the reagent becomes non-uniform under this condition, a scattering of the reagent concentration is caused during the reagent solution pipetting operation, therefore it is impossible to practise correctly the analysis operation.
Accordingly, when a partly soluble reagent or an insoluble reagent for use in the automatic chemistry analyzer is used therein, it is indispensable to practise a mixing operation immediately after starting the automatic chemistry analyzer or immediately before beginning the reagent solution pipetting operation.
So as to realize a method of a reagent mixing operation for use in the automatic chemistry analyzer, there has been developed a method of swinging a reagent vessel over a reagent refrigerator and a method of mixing a reagent with a magnetized stirrer inserted in a reagent vessel with a fluctuating magnetic field applied from the outside of the reagent vessel. Further, there has been developed a method of rotating a reagent vessel in which an outer wall of the reagent vessel is contacted to a driving apparatus.
Further, there has been developed a method of rotating a reagent cuvette in which the reagent cuvette is rotated by an eccentric structure stirrer as shown in Japanese Utility Model Laid-Open No. 17488/1980. The eccentric structure stirrer is mounted on a top portion of a rotating shaft which can move up-and-down. The stirrer is provided to be not co-axial with an axis of the reagent cuvette and moves up-and-down. A round bottom portion of the reagent cuvette is disposed on an upper convex portion of the eccentric structure stirrer and is rotated by the eccentric structure stirrer.
However, since a reagent cuvette supporter is inserted as a supporter at an upper end portion of the reagent cuvette, during a rotating mixing operation the reagent solution rises in the reagent cuvette, spills out of the cuvette, and adheres to the reagent cuvette supporter. As the round bottom portion of the reagent cuvette is supported by the convex portion of the stirrer, an engagement relationship between the stirrer and the reagent cuvette becomes unstable. Further, since a shaft for a solenoid rotates synchronously, an abrasion of the shaft occurs.